/*
 * Copyright 2009 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.openuat.android.dialogs;

import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.ActivityNotFoundException;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.net.Uri;
import android.util.Log;

/**
 * <p>
 * A utility class which helps ease integration with Barcode Scanner via
 * {@link Intent}s. This is a simple way to invoke barcode scanning and receive
 * the result, without any need to integrate, modify, or learn the project's
 * source code.
 * </p>
 * 
 * <h2>Initiating a barcode scan</h2>
 * 
 * <p>
 * To integrate, create an instance of {@code IntentIntegrator} and call
 * {@link #initiateScan()} and wait for the result in your app.
 * </p>
 * 
 * <p>
 * It does require that the Barcode Scanner (or work-alike) application is
 * installed. The {@link #initiateScan()} method will prompt the user to
 * download the application, if needed.
 * </p>
 * 
 * <p>
 * There are a few steps to using this integration. First, your {@link Activity}
 * must implement the method {@link Activity#onActivityResult(int, int, Intent)}
 * and include a line of code like this:
 * </p>
 * 
 * <pre>
 * {@code
 * public void onActivityResult(int requestCode, int resultCode, Intent intent) {
 *   IntentResult scanResult = IntentIntegrator.parseActivityResult(requestCode, resultCode, intent);
 *   if (scanResult != null) {
 *     // handle scan result
 *   }
 *   // else continue with any other code you need in the method
 *   ...
 * }
 * }
 * </pre>
 * 
 * <p>
 * This is where you will handle a scan result.
 * </p>
 * 
 * <p>
 * Second, just call this in response to a user action somewhere to begin the
 * scan process:
 * </p>
 * 
 * <pre>
 * {
 *     &#064;code
 *     IntentIntegrator integrator = new IntentIntegrator(yourActivity);
 *     integrator.initiateScan();
 * }
 * </pre>
 * 
 * <p>
 * Note that {@link #initiateScan()} returns an {@link AlertDialog} which is
 * non-null if the user was prompted to download the application. This lets the
 * calling app potentially manage the dialog. In particular, ideally, the app
 * dismisses the dialog if it's still active in its {@link Activity#onPause()}
 * method.
 * </p>
 * 
 * <p>
 * You can use {@link #setTitle(String)} to customize the title of this download
 * prompt dialog (or, use {@link #setTitleByID(int)} to set the title by string
 * resource ID.) Likewise, the prompt message, and yes/no button labels can be
 * changed.
 * </p>
 * 
 * <p>
 * By default, this will only allow applications that are known to respond to
 * this intent correctly do so. The apps that are allowed to response can be set
 * with {@link #setTargetApplications(Collection)}. For example, set to
 * {@link #TARGET_BARCODE_SCANNER_ONLY} to only target the Barcode Scanner app
 * itself.
 * </p>
 * 
 * <h2>Sharing text via barcode</h2>
 * 
 * <p>
 * To share text, encoded as a QR Code on-screen, similarly, see
 * {@link #shareText(CharSequence)}.
 * </p>
 * 
 * <p>
 * Some code, particularly download integration, was contributed from the
 * Anobiit application.
 * </p>
 * 
 * <h2>Enabling experimental barcode formats</h2>
 * 
 * <p>
 * Some formats are not enabled by default even when scanning with
 * {@link #ALL_CODE_TYPES}, such as
 * {@link com.google.zxing.BarcodeFormat#PDF_417}. Use
 * {@link #initiateScan(java.util.Collection)} with a collection containing the
 * names of formats to scan for explicitly, like "PDF_417", to use such formats.
 * </p>
 * 
 * @author Sean Owen
 * @author Fred Lin
 * @author Isaac Potoczny-Jones
 * @author Brad Drehmer
 * @author gcstang
 */
public class IntentIntegrator {

    public static final int REQUEST_CODE = 0x0000c0de; // Only use bottom 16
						       // bits
    private static final String TAG = IntentIntegrator.class.getSimpleName();

    public static final String DEFAULT_TITLE = "Install Barcode Scanner?";
    public static final String DEFAULT_MESSAGE = "This application requires Barcode Scanner. Would you like to install it?";
    public static final String DEFAULT_YES = "Yes";
    public static final String DEFAULT_NO = "No";

    private static final String BS_PACKAGE = "com.google.zxing.client.android";

    // supported barcode formats
    public static final Collection<String> PRODUCT_CODE_TYPES = list("UPC_A",
	    "UPC_E", "EAN_8", "EAN_13", "RSS_14");
    public static final Collection<String> ONE_D_CODE_TYPES = list("UPC_A",
	    "UPC_E", "EAN_8", "EAN_13", "CODE_39", "CODE_93", "CODE_128",
	    "ITF", "RSS_14", "RSS_EXPANDED");
    public static final Collection<String> QR_CODE_TYPES = Collections
	    .singleton("QR_CODE");
    public static final Collection<String> DATA_MATRIX_TYPES = Collections
	    .singleton("DATA_MATRIX");

    public static final Collection<String> ALL_CODE_TYPES = null;

    public static final Collection<String> TARGET_BARCODE_SCANNER_ONLY = Collections
	    .singleton(BS_PACKAGE);
    public static final Collection<String> TARGET_ALL_KNOWN = list(BS_PACKAGE, // Barcode
									       // Scanner
	    "com.srowen.bs.android", // Barcode Scanner+
	    "com.srowen.bs.android.simple" // Barcode Scanner+ Simple
    );

    private final Activity activity;
    private String title;
    private String message;
    private String buttonYes;
    private String buttonNo;
    private Collection<String> targetApplications;

    public IntentIntegrator(Activity activity) {
	this.activity = activity;
	title = DEFAULT_TITLE;
	message = DEFAULT_MESSAGE;
	buttonYes = DEFAULT_YES;
	buttonNo = DEFAULT_NO;
	targetApplications = TARGET_ALL_KNOWN;
    }

    public String getTitle() {
	return title;
    }

    public void setTitle(String title) {
	this.title = title;
    }

    public void setTitleByID(int titleID) {
	title = activity.getString(titleID);
    }

    public String getMessage() {
	return message;
    }

    public void setMessage(String message) {
	this.message = message;
    }

    public void setMessageByID(int messageID) {
	message = activity.getString(messageID);
    }

    public String getButtonYes() {
	return buttonYes;
    }

    public void setButtonYes(String buttonYes) {
	this.buttonYes = buttonYes;
    }

    public void setButtonYesByID(int buttonYesID) {
	buttonYes = activity.getString(buttonYesID);
    }

    public String getButtonNo() {
	return buttonNo;
    }

    public void setButtonNo(String buttonNo) {
	this.buttonNo = buttonNo;
    }

    public void setButtonNoByID(int buttonNoID) {
	buttonNo = activity.getString(buttonNoID);
    }

    public Collection<String> getTargetApplications() {
	return targetApplications;
    }

    public void setTargetApplications(Collection<String> targetApplications) {
	this.targetApplications = targetApplications;
    }

    public void setSingleTargetApplication(String targetApplication) {
	this.targetApplications = Collections.singleton(targetApplication);
    }

    /**
     * Initiates a scan for all known barcode types.
     */
    public AlertDialog initiateScan() {
	return initiateScan(ALL_CODE_TYPES);
    }

    /**
     * Initiates a scan only for a certain set of barcode types, given as
     * strings corresponding to their names in ZXing's {@code BarcodeFormat}
     * class like "UPC_A". You can supply constants like
     * {@link #PRODUCT_CODE_TYPES} for example.
     */
    public AlertDialog initiateScan(Collection<String> desiredBarcodeFormats) {
	Intent intentScan = new Intent(BS_PACKAGE + ".SCAN");
	intentScan.addCategory(Intent.CATEGORY_DEFAULT);

	// check which types of codes to scan for
	if (desiredBarcodeFormats != null) {
	    // set the desired barcode types
	    StringBuilder joinedByComma = new StringBuilder();
	    for (String format : desiredBarcodeFormats) {
		if (joinedByComma.length() > 0) {
		    joinedByComma.append(',');
		}
		joinedByComma.append(format);
	    }
	    intentScan.putExtra("SCAN_FORMATS", joinedByComma.toString());
	}

	String targetAppPackage = findTargetAppPackage(intentScan);
	if (targetAppPackage == null) {
	    return showDownloadDialog();
	}
	intentScan.setPackage(targetAppPackage);
	intentScan.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
	intentScan.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
	activity.startActivityForResult(intentScan, REQUEST_CODE);

	return null;
    }

    /**
     * Start an activity.<br>
     * This method is defined to allow different methods of activity starting
     * for newer versions of Android and for compatibility library.
     * 
     * @param intent
     *            Intent to start.
     * @param code
     *            Request code for the activity
     * @see android.app.Activity#startActivityForResult(Intent, int)
     * @see android.app.Fragment#startActivityForResult(Intent, int)
     */
    protected void startActivityForResult(Intent intent, int code) {
	activity.startActivityForResult(intent, code);
    }

    private String findTargetAppPackage(Intent intent) {
	PackageManager pm = activity.getPackageManager();
	List<ResolveInfo> availableApps = pm.queryIntentActivities(intent,
		PackageManager.MATCH_DEFAULT_ONLY);
	if (availableApps != null) {
	    for (ResolveInfo availableApp : availableApps) {
		String packageName = availableApp.activityInfo.packageName;
		if (targetApplications.contains(packageName)) {
		    return packageName;
		}
	    }
	}
	return null;
    }

    private AlertDialog showDownloadDialog() {
	AlertDialog.Builder downloadDialog = new AlertDialog.Builder(activity);
	downloadDialog.setTitle(title);
	downloadDialog.setMessage(message);
	downloadDialog.setPositiveButton(buttonYes,
		new DialogInterface.OnClickListener() {
		    @Override
		    public void onClick(DialogInterface dialogInterface, int i) {
			Uri uri = Uri
				.parse("market://details?id=" + BS_PACKAGE);
			Intent intent = new Intent(Intent.ACTION_VIEW, uri);
			try {
			    activity.startActivity(intent);
			} catch (ActivityNotFoundException anfe) {
			    // Hmm, market is not installed
			    Log.w(TAG,
				    "Android Market is not installed; cannot install Barcode Scanner");
			}
		    }
		});
	downloadDialog.setNegativeButton(buttonNo,
		new DialogInterface.OnClickListener() {
		    @Override
		    public void onClick(DialogInterface dialogInterface, int i) {
		    }
		});
	return downloadDialog.show();
    }

    /**
     * <p>
     * Call this from your {@link Activity}'s
     * {@link Activity#onActivityResult(int, int, Intent)} method.
     * </p>
     * 
     * @return null if the event handled here was not related to this class, or
     *         else an {@link IntentResult} containing the result of the scan.
     *         If the user cancelled scanning, the fields will be null.
     */
    public static IntentResult parseActivityResult(int requestCode,
	    int resultCode, Intent intent) {
	if (requestCode == REQUEST_CODE) {
	    if (resultCode == Activity.RESULT_OK) {
		String contents = intent.getStringExtra("SCAN_RESULT");
		String formatName = intent.getStringExtra("SCAN_RESULT_FORMAT");
		byte[] rawBytes = intent.getByteArrayExtra("SCAN_RESULT_BYTES");
		int intentOrientation = intent.getIntExtra(
			"SCAN_RESULT_ORIENTATION", Integer.MIN_VALUE);
		Integer orientation = intentOrientation == Integer.MIN_VALUE ? null
			: intentOrientation;
		String errorCorrectionLevel = intent
			.getStringExtra("SCAN_RESULT_ERROR_CORRECTION_LEVEL");
		return new IntentResult(contents, formatName, rawBytes,
			orientation, errorCorrectionLevel);
	    }
	    return new IntentResult();
	}
	return null;
    }

    /**
     * Shares the given text by encoding it as a barcode, such that another user
     * can scan the text off the screen of the device.
     * 
     * @param text
     *            the text string to encode as a barcode
     */
    public void shareText(CharSequence text) {
	Intent intent = new Intent();
	intent.addCategory(Intent.CATEGORY_DEFAULT);
	intent.setAction(BS_PACKAGE + ".ENCODE");
	intent.putExtra("ENCODE_TYPE", "TEXT_TYPE");
	intent.putExtra("ENCODE_DATA", text);
	String targetAppPackage = findTargetAppPackage(intent);
	if (targetAppPackage == null) {
	    showDownloadDialog();
	} else {
	    intent.setPackage(targetAppPackage);
	    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
	    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
	    activity.startActivity(intent);
	}
    }

    private static Collection<String> list(String... values) {
	return Collections.unmodifiableCollection(Arrays.asList(values));
    }

}
